The subjects receive either 2.5 mg of nebulized albuterol every 20 min for three doses or two doses of 5.0 mg of albuterol 20 min apart. Albuterol non-responsiveness is defined as a failure of the PEFR in an acutely ill asthmatic to exceed 40% of predicted following ≥7.5 mg of albuterol (2.5 mg albuterol aerosols q.20 min x3). After completion of each schedule, PEFR is repeated and the patients reexamined. Admission and discharge decisions are made according to published predetermined criteria. Patients are considered ready to be sent home if they are asymptomatic, free of accessory muscle use, have absent or diminished wheezing, and have achieved a peak flow of 60% of predicted. Those not meeting these requirements are given further treatment with adrenergic and anticholinergic bronchodilators and glucocorticoids at the discretion of the ED physician and reassessed hourly. If they subsequently meet the discharge criteria, they are released. If not, they are admitted to hospital. The false-positive admission rate with these algorithms has been found to be less than 1% and the 24-hour relapse rate less than 2%.